De Buyck et al., Bull. Soc. Chim. Belg. 89 (1980) pp. 441 ff teach the preparation of 2,2-dichloroaldehydes from aldehydes and alcohols by chlorination in dimethylformamide. This reference teaches that induction periods are minimized by the addition of 5 to 10 percent dry hydrogen chloride and that the use of dimethyl formamide as a solvent imparts beneficial stability to the reactants to form the products free of undesirable side reactions.
While the process is effective, it has been found that the dimethylformamide, an expensive solvent, could not be reused as the solubility of chlorine was markedly reduced upon completing only one reaction, the DMF recovery was poor and therefor fresh dimethylformamide had to be added.